The number of overseas immigrants has surged.

At least three times. /kloc-in the 1970 s, a large number of Chinese workers came to California to build railways. The picture shows the bronze sculpture "Pioneer" established by the people of California to commemorate the contribution of Chinese workers to economic prosperity. (Ding Gang/photo) According to the latest statistics of the Immigration Research Center, the United States has ushered in the largest immigration tide in history. In the past 400 years, tens of millions of residents from various countries have entered the United States with capital, technology and knowledge. Under their impetus, the United States gradually became stronger. Known as the "ethnic melting pot", the United States is a typical immigrant country. Its immigration history can be traced back to 1620. In the past 400 years, the United States has become a mixture of 100 countries, and even the Statue of Liberty in New York has "immigrated" from France to the United States. 1886. Immigrants came to this ideal land with dreams and crossed the ocean, which set off an immigration tide in American history. It is no exaggeration to say that immigrants created America, and immigrants developed and changed America. Attracting immigrants is the most important diplomatic task of the United States. When the United States was founded, the total family population in the United States was only 3.9 million. Except for about 760,000 blacks, almost all of them are white, and most of them are from Western Europe. Considering the Napoleonic Wars in Europe and the domestic employment environment, the early American governments had many doubts about immigration policies and formulated some policies to restrict immigration. From 1796 to 18 15, an average of 3,000 Europeans immigrated to the United States every year. After the Napoleonic Wars, peace was restored in Europe. With the demobilization of a large number of soldiers, unemployment in European countries has become more serious, and the number of immigrants to the United States has increased year by year. At this time, the United States also changed immigration restrictions for domestic construction needs. 1848 after the European revolution, the wave of immigration to the United States was even higher. From 1820 to 100 in 1920, the United States accepted about 33.5 million immigrants, which formed the immigration tide of the United States 100.